YSI 556 MPS - Manual (Page 56)

Section 6 Calibrate
YSI 556 MPS YSI Incorporated Page 50
Figure 6.15 Specified ORP Calibration Screen
4. Place the correct amount (see Table 6.1 Calibration Volumes)
of a known ORP solution (we recommend Zobell solution)
into a clean, dry or pre-rinsed transport/calibration cup.
WARNING: Calibration reagents may be hazardous to your
health. See Appendix D Health and Safety for more information.
NOTE: Before proceeding, ensure that the sensor is as dry as
possible. Ideally, rinse the ORP sensor with a small amount of
solution that can be discarded. Be certain that you avoid cross-
contamination with other solutions.
5. Carefully immerse the sensor end of the probe module into
the solution.
6. Gently rotate and/or move the probe module up and down to
remove any bubbles from the ORP sensor.
NOTE: The sensor must be completely immersed. Using the
recommended volumes from Table 6.1 Calibration Volumes
should ensure that the sensor is covered.
7. Screw the transport/calibration cup on the threaded end of
the probe module and securely tighten.
NOTE: Do not over tighten as this could cause damage to the
threaded portions.